If you've ever ridden any of the super high speed trains (in excess of 130 mph) in Asia or Europe, well, they're pretty cool. But after cool there's the practical. It seems extravagant to think of a $42 billion dollar bullet train project while California is in the midst of one of its worst economic disasters.

And what's more, the UC Berkeley report found the way the Rail Authority determined whether the riders would rather drive or fly or take a bullet train was flawed. And that means you can't predict whether a bullet train will experience "healthy profits or severe revenue shortfalls, "according to principal investigator Samer Madanat of UC Berkeley.

While California, especially Southern California is steeped in its "gotta have a car" culture in order to get around, slowly but surely that trend is changing. "Ridership in public transit is up and cities and other jurisdictions have a much stronger focus" on it now, says Mark Peterson, partner in the transportation consultant firm of Fehr & Peers with headquarters in Walnut Creek and offices throughout California and the rest of the country.

Peterson sites the Coaster trains in San Diego County as a successful example of the growing popularity of public transit. The Coaster connects San Diego to it's north county. Besides being full of daily commuters, it also runs special trains to carry fans to Padre games.

"Los Angeles is one of the emerging leaders in high speed rail," Peterson adds. "It has a strong rail system already and now they're going to be building subways to the west side in years to come. It's going to create jobs, it's planning for the future and we can't neglect our infrastructure."

But we can't ignore two factors -- time and cost -- which equals ridership. Take for example, the trip from Los Angeles to San Francisco. A bullet train would get you there in say 2 hours and 40 minutes. Would it be competitive to flying or driving? And then how much would it cost?

Those are the kinds of questions that still need to be answered which, according to the UC Berkeley study, were not.

The UC Berkeley review of the Rail Authority's forecast is part of the $2.25 billion in federal stimulus funds for high speed rail in California. It's raised a lot of questions about the state's high speed rail, hopefully they can be answered before the calls come in to really derail the project.